Stefan W. Hell

Aula der Universität Zürich

Nanoscopy with focused light

Professor Hell is best known for his work leading to the invention and development of Stimulated Emission Depletion (STED) microscopy. He was able to show that one can substantially improve the resolving power of the fluorescence microscope, which had been previously limited to about half the wavelength of light (>200 nm). Professor Hell was the first to demonstrate, both theoretically and experimentally, how one can decouple the resolution of the fluorescence microscope from the diffraction of light and increase the resolution to the nanometer scale. Ever since the work of the famous physicist Ernst Karl Abbe, who laid the foundations of modern optics (around 1873), this feat was thought to be impossible. The greatest impact of super-high resolution microscopy, such as STED, has been felt so far in the life sciences and medicine, and more broadly within the field of cell biology. Through the appropriate design and selection of fluorescent dyes, and methods for specific labeling of biological molecules it now becomes possible to probe an unbelievable array of complex biological processes at low nanometer resolution - truly at the molecular level.